1. Field of the Invention
The present invention relates to a substrate processing apparatus.
For example, the present invention may be effectively applied to a heat treatment apparatus (furnace) configured to perform a heat treatment process, such as film forming, annealing, oxidation, diffusion, and reflow treatment for carrier activation or planarization after ion implantation, so as to form an oxide film, a metal film, or a semiconductor film on a semiconductor wafer (hereinafter, referred to as a wafer) for forming a semiconductor integrated circuit device (hereinafter, referred to as an IC) on the wafer.
2. Description of the Prior Art
In a method of manufacturing an IC, a heat treatment apparatus such as a batch type vertical hot-wall chemical vapor deposition (CVD) apparatus is widely used to deposit a material such as silicon nitride (Si3N4), silicon oxide (SiOx), and polysilicon on a wafer.
The batch type vertical hot-wall CVD apparatus (hereinafter, referred to as a CVD apparatus) includes: an outer tube; an inner tube installed inside the outer tube to form a process chamber; a heating device (heater) configured to heat the inside of the outer tube; a manifold on which the outer and inner tubes are placed and to which an exhaust pipe and a gas introducing pipe are connected for exhausting the process chamber and supplying gas to the process chamber; and a boat configured to hold a plurality of vertically arranged wafers and be loaded into the process chamber.
When the boat in which a plurality of wafers are held is loaded into the process chamber through a lower furnace port, a film-forming gas is supplied to the process chamber through the gas introducing pipe, and at the same time, the process chamber is heated by the heating device, so that CVD films can be deposited on the wafers.
Such a CVD apparatus of the related art, for example, a CVD apparatus disclosed in Patent Document 1, includes a manifold (furnace port flange) made of a metal.
Since the metallic manifold has a thin plate thickness and low heat capacity, heat can be easily dissipated to the outside of a furnace port.
[Patent Document 1] Japanese Unexamined Patent Application Publication No. 2002-334868
However, such a CVD apparatus including a metallic manifold has a problem in that the metallic manifold is corroded by reaction products, which are generated from reaction gas and cleaning gas and attached to the metallic manifold.
Moreover, as the size of ICs reduces, metal emission from the metallic manifold of the CVD apparatus causes other problems. Therefore, recent manifolds, outer tubes, and seal caps are made of quartz.
In a semiconductor manufacturing apparatus, a vacuum seal part corresponding to an O-ring is provided at a flange part of a quartz outer tube or the like, and if the seal surface (joining surface) of the vacuum seal part is damaged (or scratched), there may be a problem such as leakage of process gas. A part such as the outer tube has a seal surface at its bottom surface, and if the outer tube is detached from the semiconductor manufacturing apparatus and stored or temporarily placed on a floor, the seal surface of the outer tube can be damaged due to contaminants although the floor is covered with a clean sheet.
Moreover, in some cases, a flange of an exhaust pipe of the outer tube may be installed at a position lower than the bottom surface of the outer tube. In this case, the weight of the outer tube can be directly applied to the flange of the exhaust pipe, and thus the exhaust pipe can be broken.
Furthermore, in the case where a quartz part is placed on a floor, contaminants can be attached from a floor to the seal surface of the quartz part, and the contaminants may enter into a furnace to pollute the inside of the furnace.